DuaFire Voice Amplifier Portable Microphone with Waistband for Classroom Teachers, Speakers, Yoga Instructors, Gym Directors, Coaches, Presentations, Seniors and Tour Guides (Black) Small & Portable Super Powerful Voice Amplifier/Speaker. Size is 4.13in x 3.31in x 1.38in (105mm x 84mm x 35mm). Rechargeable lithium batteries that last 10 hours of continuous use before needing a charge. A Green LED Light will indicate that battery is fully charged Very loud, excellent clarity. Sound covers over 4,300 square feet (400 Square Meters). The voice amplifier is the best voice amplifier to get your message out to everyone, no matter what the crowd is. We designed our personal amplifier to be comfortably portable while still being sturdy enough to use in almost any situation. The mini voice amplifier is designed for teachers, preachers, coaches, or anyone who needs to get their message out The small yet powerful amplifier with speakers provides the loud, clear output required for high quality voice amplification. It economical, portable, feature rich and high quality. It also can be used as an MP3 speaker for Smartphone, audio player, etc., connected by audio cable(male to male). Comes with Headset microphone, Charger cable, MP3 cable, adjustable waist or neck band and a removable belt clip We are so confident that our mini voice amplifier will be the best voice amplifier microphone system. Any query, please kindly contact us, we will do our best for you.